The role of perception in reading has been underestimated because it is primarily the perception of letter form (what is it?) that has been investigated. A recent study shows that good and poor sixth grade readers can be differentiated by the amount of time they require to encode order information (where is it?). Spatial redundancy is a variable of orthographic regularity that is dependent upon the encoding of order information. A recent study shows that spatial redundancy operates at the perceptual rather than at the inferential level. Research emanating from our laboratory over the past two years points to earlier site for the origin of reading disability than we had originally envisaged. We propose to use simple tasks to intensively investigate the initial 150 msec of visual information processing in conjunction with reading ability. Visual stimuli will be presented at exposure durations varying from 5 to 150 msec, followed by a masking stiumulus to prevent additional processing during the persistence stage. A four-alternative forced-choice procedure will be used to evaluate the amount of information actually extracted by good and poor readers at each exposure duration. The types of information to be investigated include color, spatial location, and item information. The extraction of item information will be investigated both independently of order information and in conjunction with order information. If poor readers require more time to encode color information as well as order information, a general deficit at the initial encoding stage will be indicated. If poor readers show a specific encoding deficit for order information, the relevance to the reading process will be readily interpretable in terms of the spatial redundancy present in printed English that serves to facilitate the visual resolution of letters. Previous failures to find conclusive evidence for perceptual deficits in reading disability may be due to the fact that the perception of spatial location has been largely overlooked and that the perceptual deficit hypothesis has been cast primarily in terms of what is eventually perceived rather than in terms of the time required for the formation of the percept.